A Co Antrim plastics firm which put the roof over the heads of London's Olympians has seen its profits more than double to £5.2m.

And Brett Martin has said it aims to continue that upwards trend "despite much tougher headwinds".

Brett Martin Limited's pre-tax profits grew from £2.4m in 2013 to £5.2m last year, to December 31.

The Newtownabbey-based plastics and plumbing products business also saw its turnover increase by almost £10m in the year - rising to almost £110m.

One of its latest high-profile deals included producing the clear-plastic roof "lights" in the Olympic Park Stadium, where Ireland clashed with Italy yesterday.

A spokesman for the company said: "The last 12 months has seen Brett Martin continue to build on distribution partnerships around the world to supply high-quality specialist plastic products for the construction industry.

"Favourable conditions in 2014 in many markets, particularly the UK, combined to give a strong financial performance," he said.

"In 2015, projects like the refurbishment of the roof on Queen Elizabeth Olympic Park Stadium in London underpinned by a strong demand for our products has helped our business to grow and this is a trend we aim to continue in the years to come despite much tougher headwinds in many markets and the negative impact of the strong pound on export profitability."

The business has retained a consistent workforce, employing 559 staff according to the latest set of accounts.

Overall staff costs rose to just short of £20m for the year. That was up from £18.6m a year earlier.

Brett Martin's company directors received a total of £1.2m - the highest paid £330,000.

That was up from £299,000 a year earlier.

The company said in its report that the "directors consider the results for the financial year and the position of the company at the financial year end to be satisfactory".

And it said it will "seek every opportunity to increase profitable turnover".

And aside from its Olympic credentials, Brett Martin has also been involved in the art world.

Just last year the firm's Marlon ST Longlife product - a structurally strong, lightweight polycarbonate sheet - was used to construct the walls of a mind-bending illusion by artist Alex Chinneck at Covent Garden.

Brett Martin was also part of a team of suppliers who helped redevelop the stadium which will host five games during this year's Rugby World Cup.

Speaking about the roof work, which was part of the one of the largest infrastructure projects ever to take place in the UK, William Martin, production manager at the firm's Marlon CS plant, said: "We are incredibly proud to have supplied a critical component in the construction of the roof canopy. The project is a feat of production and delivery logistics and upon completion of the stadium, we have demonstrated our technical excellence and expertise in the delivery of specialist and large-scale roof lighting projects

"Working closely with the project architects and contractors, we were able to provide substantial technical assistance and guida nce."